The Last Venus Transit in this Century – 6 Jun 2012

You won’t want to miss this event on Jun 6 (Wednesday). This is an event which only happens about twice in a century and won’t happen again until the year 2117!

The event is known as The Transit of Venus.

What is that?

Transit of Venus happens when the planet Venus passes directly between the Earth and the Sun, and from Earth, we can see Venus as a small black disk moving across the face of the Sun.

A Venus (or Mercury) transit is actually similar to a solar eclipse; in a solar eclipse, the Moon passes directly between the Earth and the Sun, and since the apparent size of the Moon is almost the same as the Sun as view from Earth, the Moon will block out the whole Sun. Venus (or Mercury) although is much bigger than the Moon, it is also very much further away, thus Venus will appear much smaller and is unable to cover the whole Sun. Instead, it will appear as a small black disk against the Sun big bright disk, and moves slowly across the Sun’s face which can last for hours.

Venus Transit of 2004. Credit: Gradient Lok

Transit of Venus occurs in pairs of 8 years apart separated by 105.5 years and 121.5 years. The last was 8 years ago in 2004, the next one is this coming Jun 5/6, and if you miss this one, I don’t think you will see this event again – the next one will be 105.5 years later in Dec 2117.

In Malaysia, the timing is as follows:

In Peninsular Malaysia, the Sun rises around 7 am, so we will miss Contact I and II. Venus is already transiting the solar disk when the Sun rises. However, we can observe the event until it ends at 12:49 pm.

Sabah and Sarawak will have a better chance to see Contact I and II as the Sun rises, although you may need a clear and unobstructed horizon to see sunrise. In Sabah, sunrise time for Sandakan is roughly 5:50 am, Kota Kinabalu 6 am. In Sarawak, sunrise time for Miri is roughly 6:12 am, Kuching 6:30 am. For sunrise time in your town, just type “town-name sunrise time” into Google.

My initial plan for this post is to include everything on Venus Transit, from its history to how to observe. But now I decided to give up the plan for two reasons: (1) I’m running out of time to write, (2) a lot of people had done a better job than me in explaining all the details, so I think I’ll direct you to the links for all the interesting details.